Metformin and berberine can regulate blood glucose, potentially causing hypoglycemia if used carelessly, and can alter neural circuitry regulating blood sugar.

“I think that many of the effects can be quite potent. They can happen in both the immediate term in terms of regulating blood glucose, they can send you hypoglycemic if you aren't careful, they can also cause longstanding changes to the neural circuitry that regulates blood sugar over time.”